Recorder



y 16, 1961 M. TRAlTE EIAL 2,984,535

RECORDER Filed Dec. 50, 1957 21 4 Sheets-Sheet 1 ELECTRON sum MR TQZFW CHARLES MOLNQR ATTORNEY May 16, 1961 M. TRAITE ETAL RECORDER Filed Dec. 30, 1957 4 Sheets-Sheet 2 ELECTRON/C SWITCH UNBLQNKING C/ECU/T' READ Y s W/TC H 7'0 CONTROL GE/D F TUBE OUT

FL/P- FL 0P,

0N0 C/ECU/T,

DEFL

FLIP-FLOP? HND as TEHCE RESET sW/TCH FLIP- FLO/ 3 PRPEE DRIVE AND C [ECU/7% TATE.

OFF F] OFF INVENTORS MQX TEFHTE CHARLES MOLNQF? HTTQENEY y 16, 1951 M. TRAITE ETAL 2,984,535

RECORDER Filed Dec. 30, 1957 4 Sheets-Sheet 3 OUT 2? FROM 4-0 VERT Y'VY N 7 DEF L OFF ON FPO/W 37 OFF OFF OUT TO 0N 5+ 5+ INVENTORS MAX TRHIT'E CHARLES MOLNQE TTO ENE? y 9 M. TRAITE EIAL 2,984,535

RECORDER Filed Dec. 30, 1957 4 Sheets-Sheet 4 O o O O O O O O O O T5711 Z4 21 24a.

INVENTORS MAX TRFHTE l CHARLES MOLNHR B United States Patent RECORDER Max Traite, North Brunswick, N.J., and Charles Molnar, South Hadley, Mass., assignors to Gulton Industries, Inc, Metuchen, N.J., a corporation of New Jersey Filed Dec. 30, 1957, Ser. No. 705, 898 4 Claims. (Cl. 346-74) Our invention relates to the recording of repetitive or transient waveforms in a form which may be easily read and retained permanently. In particular, our invention relates to the production of permanent recordings of electrical phenomena onelectrosensitive paper by means of a cathode-ray tube in the face of which is embedded a plurality of fine wire conductors which go thlrjough the glass from the insde to the outside of the tu e.

At the present time, it is necessary to use elaborate photographic equipment in conjunction with standard cathode-ray tubes in order to obtain permanent recordings of the phenomena displayed on the face of the tube. These methods are expensive and cannot be used to record transient phenomena unless some means are employed to make the transient phenomena repetitive so they may be retained on the face of the tube for sufficient time to permit exposing of the film. In addition, it is necessary to develop the film before the recorded material may be examined.

Our invention overcomes the inherent disadvantages which reside in the photographic recording devices by the employment of a special cathode-ray tube in the face of which is contained a plurality of fine wires with one end of each wire within the evacuated volume of the tube and the other end outside the tube. In conjunction with the cathode-ray tube we employ a conductive plate which is parallel to and spaced from the tube face. Between the tube face and the conductive plate We place an electrosensitive paper, such as has been described as a facsimile recording paper on page 928 of Van Nostrand, International Dictionary of Physics and Electronics (1956), and which changes color when an electric current flows through it.

It is a principal object of our invention to provide a recorder which will produce permanent records of both repetitive and transient electric waves.

It is a further object of our invention to provide such a recorder wherein such recordings may be examined immediately and without the need for further processing.

It is a still further object of our invention to provide a cathode-ray tube for use with such a recorder.

It is a still further object of our invention to provide circuitry for synchronizing the scanning of the tube face and the movement of the paper.

Other objects and advantages of our invention will be apparent during the course of the following description when taken in conjunction with the accompanying drawings wherein:

Figure 1 is a side-elevational view of a portion of a cathode-ray tube of our invention, showing the glass face somewhat enlarged and in cross-section,

Figure 2 is an end view of the portion of the glass face of the tube of Figure 1 showing the position of one line of wires which are embedded in the glass face and are bent so as to be parallel to the glass face.

Figure 3 is a view of a portion of recording paper showing an electric wave which has been recorded thereon using the teachings of our invention,

Figure 4 is a view of a portion of the recording paper showing the ready and reset switching fingers,

Figure 5 is a block diagram of the electronic elements used to synchronize the switching mechanisms of our invention,

Figure 6 is a block diagram showing the means by which the paper is moved in synchronization with the sweep circuitry retrace,

Figure 7 is a schematic diagram of the electronic switch usedin our invention Figure 8 is a schematic used in our invention,

Figure 9 is a schematic used in our invention,

Figure 10 is a front view of the face of the cathoderay tube of our invention showing the mosaic of fine wires protruding therefrom, and

Figure 11 is an elevational View of the two conductive plates of our invention showing the charging switches schematically.

In the drawings, wherein, for the purpose of illustration are shown preferred embodiments of our invention, the numeral 20 designates the cathode-ray tube, generally. Tube 20 comprises an electron gun with the usual source of electrons, control grid, horizontal and vertical deflection plates or coils, a glass or metal envelope, glass face 21 and collector anode 22 which eliminates the emission of secondary electrons from the glass and wires. A positive potential of the order of, for example, 200 volts is applied to collector anode 22. Wires 23 are embedded in face 21 and traverse the cross-section of face 21 perpendicular to the surface of face 21. Wires 23 go through face 21 from its inner to outer surface so that the inner ends of wires 23 are capable of making contact with the electron beam of tube 20. The outer ends of wires 23 may be bent over parallel to the face of glass face 21 as shown in Figure 2 or may be left so each wire 23 is a straight line as shown in Figure 10. A voltage within the range, say 500 to 1000 volts, is applied to plate 24 from source of high voltage (shown diagrammatically in Figure 1) so that are 26 occurs whenever the electron beam contacts a Wire 23. The resulting are 26 causes a spot in sheet of paper 25, particularly, an electrosensitive type such as manufactured and sold commercially by the Haloid Corporation, or any other material, such as cloth, which is readily charred by the arc discharge. As paper 25 is moved across the face of tube 20, a curve such as is illustrated by 27 in Figure 3 is recorded.

Paper 25 may be moved across the face of tube 20 at a constant velocity or it may be moved in frames so that it remains stationary with respect to glass face 21 during the electron beams trace time and moves during the retrace time and successive trace times during which the tube face is blanked, as described below. In Figure 4 paper 25 carries holes 28 and 29; holes 28 are utilized to actuate ready switch 30 and holes 29 are utilized to actuate reset switch 32. Switch 30 comprises metal finger 34 and metal plate 31, disposed on opposite sides of paper 25 so that contact between them is made through a hole 28. Switch 32 is similar to switch 30 and comprises metal finger 35 and metal plate 33 so placed that contact between them is made through a hole 29.

In Figure 5, when ready switch 30 is closed, signal of the shape of 42 is applied to the inputs of Electronic Switch 36 and AND Circuit; 38 from the sweep amplifier (not sown). The sweep amplifier is of the usual type such as is described in Principles of Radar, by the Staff of the Radar School of MIT, published by McGraw-Hill diagram of the AND circuit diagram of the AND circuit aaaaese 3 Book Company, Inc., 1946, page 3 et seq. The output of Electronic Switch 36 is fed to Unblanking Circuit 39, which is of the usual type such as is described in Instruction Manual on Type 545 Oscilloscope, by Tektronix Inc., PO. Box 831, Portland, Oregon, at page 10. The output of Unblanking Circuit 39 is fed to the control grid of tube and to one of the inputs of AND Circuit 4i and signal of the shape of the trace being recorded, illustrated as 43, is applied to the other input of AND Circuit 44 from the vertical deflection circuit of tube 26 (not shown). The vertical deflection circuit is of the usual type such as is described in Instruction Manual on Type 545 Oscilloscope, by Tektronix Inc., PO. Box 831, Portland, Oregon, at page 2.

The output of AND Circuit, is fed to one of the inputs of Flip-Flop 41, whose second input may be grounded through reset switch 32. The output of Flip- 'Flop 4?. is fed to the second input of AND Circuit 33. whose output is fed to one of the inputs of Flip-Flop, 37 and thence to a second input of Electronic Switch 36. The second input of Flip-Flop, 37 may be grounded through reset switch 32.

Switch in Figure 6 is mechanically ganged with ready switch 30 (details not shown) so that switch 45 closes when switch 31 closes and switch as opens when switch 30 opens. Signal output from AND Circuit 38 is applied to one input of Flip-Flop 44 whose second input is grounded when switch 45 is closed. The output of Flip-Flop i i is utilized to actuate paper drive 46 when when Flip-Flop 44 is off.

Paper drive 46 (details not shown) comprises a small 60 c.p.s. A.-C. motor. Paper 25 is wound around the extension of the motor shaft and the operation of the motor is controlled by a relay which is activated by a thyratron which is controlled by Flip-Flop In Figure 7, input signal of the shape of 42 is applied to resistor through switch 30 and input signal of the shape of curve 48 is applied to resistor 51. Output to Unblanking Circuit 39 is taken from the junction of resistor 52 and diode 49 and is of the shape of curve 47. Battery 53 may be used to provide proper biasing levels on the diode. When signal 48 is in its Off condition, diode 49 is biased in the reverse direction, and has a very high impedance, in the order of megohms. Hence any signal 42 appearing at resistor 50 is blocked from passing through the diode 49. When signal 48 is in its On condition, the diode is biased in its forward direction, and has a low impedance of the order of tens of ohms. Hence any signal 42 appearing at resistor 50 is transmitted through to Unblanking Circuit 39 with only slight attenuation. Such a circuit has been described in The Design of Switching Circuits, by Keister, Ritchie and Washburn, published by D. Van Nostrand Company, Inc., 1951, at page 214.

In Figure 8, input 43 from the vertical deflection circuit is combined with input 58 from Unblanking Circuit 39 through resistors and 56. The On condition of signal 53 is just barely insufiicient to turn the tube On. A small signal from the vertical deflection plates, combined with the On condition of signal 53, is sufiicient to turn the tube On. The combined On signals are amplitied in tube 49 which is operated so that there is only a small region between cutoff and saturation, and a small part of the On signal from the vertical deflection plates, when combined with the On signal from Unblanlting Circuit 39, is sufiicient to drive tube 54 into saturation. Resistor 55a is the plate load resistor and the output of AND Circuit 40, in the shape of curve 75, is applied to Flip-Flop 41 through resistor 57.

In Figure 9, input from the sweep amplifier (not shown) of the form of signal 42 is applied to differentiating capacitor 61 and is differentiated by capacitor 61 and resistor 62 so that the signal applied to the grid of tube 59 is of the form of curve 66. Resistor 64 is the plate load resistor of tube 59 and resistor 65 is that of tube s 60. Signal of the form of 68 is applied to the control grid of tube 60 through coupling capacitor 63 and resistor 70, and signal of the form of 67 is applied to the control grid of tube 66 through resistor 71 from Flip-Flop 41. The output signal from the plate of tube 60 is of the form of 69 and is fed to Flip-Flop, 37. Tube 60 is biased so that signal 68 alone or the On condition of signal 67 alone is insufficient to turn tube 66 On. When both are applied to the grid of tube 60 simultaneously through resistors 76 and 71, respectively, the grid signal 72 is suflicient to turn tube 60 On, and an inverted signal of the portion of signal 68 that is coincident with the On state of signal 67, appears on the plate of tube 60.

In Figure 11, voltage is applied to plate 24 through switches 73 and 74 from a high voltage source of the order of, for example, 500 to 1000 volts when high speed transient recording is desired and voltage is applied to plate 24a, which is just wide enough to cover a single line of vertical wires 23, through switches 7'3 and 74 from the high voltage source for all other types of recording.

It is also within the contemplation of our invention to utilize recorders with plates 24 and 24a alone as well as in the combination illustrated in Figure 11 and other combinations of conductive plates covering a plurality of lines of wires 23. We also contemplate using the shape of the portion of wires 23, which are external to 20, as illustrated in Figure 2 or Figure 10 in connection with the various combinations of conductive plates.

To record transient or repetitive functions whose major components do not exceed about 3 kilocycles, it is only necessary to use a single vertical line of wires 23, a narrow plate 24a and vertical scanning of the electron beam only. Paper 25 is moved horizontally across the face of glass face 21 at a constant velocity of up to about inches per second. A high potential is applied to plate 24a and since the electron beam is essentially at ground potential, arc 26 will be formed between plate 24a and the wire being scanned by the beam thereby leaving a charred spot in paper 25. It should be noted that the paper movement with this type of recording is continuous and not frame-by-frame as will be described later for the recording of high speed transient phenomena.

To record high speed repetitive functions whose major components do not exceed about 50 megacycles, a narrow plate 24a, and a single vertical line of wires 23 are employed. The repetitive waveform under study is frozen on face 21 by conventional means, using a horizontal sweep circuit such as is described in Instruction Manual on Type 545 Oscilloscope, by Tektronix Inc., PO. Box 831, Portland, Oregon, at pages 4 and 5, sections on Triggering Level and Stability Control. Then the frozen pattern is caused to drift across the face of tube 20 by slightly offsetting the stability control. This drift is at the same rate or at some synchronized multiple or fraction of the rate at which paper 25 passes across glass face 21 and is of the order of .1 to 10 inches per second. In this type of recording, also, the paper movement is substantially constant and not frame-by-frame.

For recording high speed transients, plate 24 of Figure 11 is used in conjunction with the mosaic of wires 23 such as is shown in Figure 10. Paper 25 progresses across face 21 frame-by-frame; being moved during the retrace time of input signal 42 and the time the tube face is held blank as described below.

The operation is as follows:

Switches 30 and 32 close when a hole 28 or 29 are respectively aligned with them. Electronic Switch 36 is On when Flip-Flop, 37 is On and Off when Flip-Flop, 37 is Off. When Electronic Switch 36 is On, a signal on its input appears at its output. Flip-Flop, 37 can be either On or Off. It changes state whenever an On signals is applied on either of its two inputs. Flip-Flop 41 and Flip-Flop 44 are identical to Flip-Flop, 37 in operation.

AND Circuit, 40 puts an On signal at its output when ts ta a there are two On signals at its inputs and puts an Oif signal at its output at-all other times. The required inputs are anOn signal from Unblanking Circuit 39 and a trans ient from the vertical deflection circuits of tube 20. When AND Circuit; 40-puts an On signal at its output, a transient is being recorded.

AND Circuit 38 puts an On signal at its output only when signals are simultaneously present on both its in puts. One input signal is present when Flip-Flop; 41 is On and the other is present during the retrace of curve 42 (the negative-going portion of the sawtooth from the sweep generator).

Unblanking Circuit 39 is On when there is signal at its input and when Unblanking Circuit 39 is On, the control grid of tube 20 is positive, permitting a trace on glass face 21. When Unblanking Circuit 39 is Off, there is no trace on glass face 21.

'When switch 30 is closed through a hole 28 in paper 25, paper 25 is in position for recording and switch 32 is open. .Electronic Switch 36 is On, Flip-Flop, 37 is On, AND Circuit 38 'is Oif, Flip-Flop: 41 is Off and AND Circuit; 40 is Off. A transient signal 43 puts a signal on the Vert 'Defl" input of AND Circuit 40 and since there is already a signal on its other input from Unblanking Circuit 39, AND Circuit 40 turns On thereby turning Flip-Flop 41 On.

At the end of the transient recording and the trace period of signal 42, AND Circuit 40 turns Off. AND Circuit 38 turns On due to the On signal from Flip-Flop 41 and the retrace of signal 42, thereby turning Flip-Flop 37 Off. This in turn turns Electronic Switch 36 and Unblanking Circuit 39 Off and the trace is removed from glass face 21. At the end of the retrace of signal 42, AND Circuit 38 turns Off.

Paper 25 now starts to move to change frames and in an intermediate position between frames switch 32 closes, turning Flip-Flop; 37 On and Flip-Flop 41 Off and Flip- Flop 37 turns Electronic Switch 36 On. When paper 25 reaches the next frame position, switch 32 is Off and switch 30 is On and the sweep signal passes through Electronic Switch 36 and Unblanking Circuit 39 and applies a trace to the control grid of tube 20. The recorder is now ready to record another transient.

The drive of paper 25 is synchronized as follows: switch 45 is mechanically coupled to switch 30 and when switch 45 is closed, AND Circuit 38 is Off and Flip-Flop 44 is Off. When AND Circuit 38 turns On during a retrace of signal 42 after a transient, Flip-Flop 44 turns On thereby starting paper drive 46. AND Circuit;,, 38 turns Off after the retrace of signal 42. When paper 25 has reached its next frame position, switch 45 closes, turning Flip-Flop 44 Off and paper drive 46 stops.

While we have described our invention by means of specific examples and in specific embodiments, we do not wish to be limited thereto, for obvious modifications will occur to those skilled in the art without departing from the spirit of our invention or the scope of the subjoined claims.

Having thus described our invention, we claim:

1. In a recording device of the class having an evacuated cathode-ray tube with a glass face and a plurality of wires extending through said glass face from within said evacuated tube to outside said tube in combination with a conductive plate external of said tube and parallel to said face, means for applying voltage to said conductive plate, and an electrosensitive paper positioned between said glass face and said conductive plate, the improvement comprising said conductive plate being divided into a first conductive plate and a second conductive plate, said plurality of wires being arranged in a mosaic over substantially all of said glass face, said first conductive plate being narrow and coextensive with and parallel to a single line of said mosaic of wires and adjacent to one edge of said glass face, said second conductive plate being opposite the remainder of said mosaic of Wires, scanning means applied to said cathode-ray tube, means for moving said paper with respect to said glass face and said conductive plates in synchronization with said scanning means, and means for connecting said voltage applying means to either of said conductive plates such that low speed transients and high speed repetitive functions applied to said scanning means are recorded on said paper when voltage is applied to said first conductive plate and such that high speed transients applied to said scanning means are recorded on said paper when voltage is applied to said second conductive plate.

2. In a recording device of the class having an evacuated cathode-ray tube with a glass face and a plurality of wires extending through said glass face from within said tially all of said glass face, said first conductive plate being narrow and coextensive with and parallel to a single line of said mosaic of wires and adjacent to one edge of said glass face, said second conductive plate being opposite the remainder of said mosaic, scanning means applied to said cathode-ray tube, means for moving said paper with respect to said glass face and said conductive plates, and means for connecting said voltage applying means to either of said conductive plates such that low speed transients and high speed repetitive functions applied to said scanning means are recorded on said paper when voltage is applied to said first conductive plate and such that high speed transients applied to said scanning means are recorded on said paper when voltage is applied to said second conductive plate.

3. A recording device comprising in combination a cathode-ray tube containing a source of a beam of electrons, an insulating target forming the face of said tube interposed in the path of said beam of electrons, said target including a plurality of separate wires embedded in and extending through said target in a direction substantially transverse to the thickness of said target, the wire ends forming a preselected pattern on the inner and outer surfaces of said target, scanning means for directing said beam of electrons to said target thereby to contact said wires progressively, means for applying signal to said scanning means, a first conductive plate and a second conductive plate spaced from and extending substantially parallel to the outer surface of said insulating target transverse to the direction of said wires, said first conductive plate being narrow and coextensive with and parallel to a single line of said wires and adjacent to one edge of said insulating target, said second conductive plate being opposite the remainder of the plurality of said wires, means for applying voltage to said conductive plates, means for connecting said voltage applying means to either of said conductive plates thereby maintaining a substantial difference of potential between said wires and at least one of said conductive plates, a sheet of paper interposed between said insulating target and said conductive plates and movable in a direction substantially parallel to the surface of said insulating target such that when said wires are contacted by said beam of electrons a series of are discharges occur which are recorded as a series of spots on said interposed sheet of paper, signals from low speed transients and high speed repetitive functions being recorded when there is a substantial difference of potential between said first conductive plate and said wires, signals from high speed transients being recorded when there is a substantial difference of potential between said second conductive plate and said wires.

4. A recording device comprising in combination a cathode-ray tube containing a source of a beam of electrons,

posed in the path of said beam of electrons,

an insulating target forming the face of said tube intersaid target including a plurality of separate wires embedded in and extending through said target in a direction substantially transverse to the thickness of said target, the wire ends forming a preselected pattern on the inner and outer surfaces of said target, scanning means for directing said beam of electrons to said target thereby to contact said wires progressively, means for applying signal to said scanning means, a first conductive plate and a second conductive plate spaced from and extending substantially parallel to the outer surface of said insulating target transverse to the direction of said wires, said first conductive plate being narrow andcoextensive with and parallel to a single line of said wires and adjacent to one edge of said insulating target, said second conductive plate being opposite the remainder of the plurality of said wires, means for applying voltage to said conductive plates, means for connecting said voltage applying means to either of said conductive plates thereby maintaining a substantial difference of potential between said wires and at least one of said conductive plates, a sheet of paper interposed between said insulating target and said conductive plates and movable in a direction substantially parallel to the surface of said insulating target in synchronization with said scanning means such that when said wires are contacted by said beam of electrons a series of arc discharges occur which are recorded as a series of spots on said interposed sheet of paper, signals from low speed transients and high speed repetitive functions being recorded when there is a substantial difierence of potential between said first conductive plate and said wires, signals from high speed transients being recorded when there is a substantial difference of potential between said second conductive plate and said wires.

References Cited in the file of this patent UNITED STATES PATENTS 2,015,570 Sabbah et a1 Sept. 24,- 1935 2,097,392 Finch Oct. 26, 1937 2,425,003 Potter Aug. 5, 1947 2,501,791 Silverman Mar. 28, 1950 2,716,826 Huebner Sept. 6, 1955 2,777,745 McNaney Jan. 15, 1957 2,829,025 Clements et a1. Apr. 1, 1958 

